1. Field of the Invention
The present invention relates to a multi-access local area network which allows an effective data transmission for MIDI data and the like.
2. Prior Art
As a local area network (i.e., LAN) using a multi-access bus, a LAN of a type of carrier sense multiple access (shortened as "CSMA") is known. Such CSMA-type LAN performs a carrier sensing and is designed to acknowledge an existence of signals on the bus prior to the data transmission. On the other hand, a CSMA/CD-type LAN is known as an improve type of the CSMA-type LAN. The term "CSMA/CD" is known as CSMA with Collision Detection. In the CSMA/CD-type LAN, a current station detects whether or not a data collision is occurred during a transmission of frames, so that the station can judge whether or not the `transmission is completed. A so-called "Ethernet" is well known as the CSMA/CD-type LAN. In these of LANs, a carrier detection system (or collision detection system) does not depend upon the frame form to be used or the coding method to be if it satisfies the predetermined conditions.
In the above-mentioned LANs, it may be possible to transmit the MIDI data (i.e., data based on the standard of Musical Instruments Digital Interface) by a predetermined frame form. In this case, the frame form depends on the LAN to be actually used, so that MIDI data should be stored in a data portion of the frame to be transmitted. This means that a gateway (or protocol conversion) is made by the software. Thus, transmit/receive-side adapter circuits to be connected between the bus and a MIDI musical instrument must be complicated in configuration or the cost thereof should become higher, which is a drawback for the conventional LAN.